Sheet-handling apparatus



. Aug. 19,1969 R. J. BROWN n we Y Filed Oct.' 11, 1967 FIGJ W) 50 I48INVENTOR FIG.2 ROY J. BROWN ATTORNEYS Aug. 19, 1969 Filed Oct. 11. '19s?FIG.3

R. J. BROWN SHEET-HANDLING APPARATUS 6 Sheets-Sheet 2 mvlzuwn Rev J.BROWN ATTORNEYS 19, 1969 R. J. BROWN 3 SHEET-HANDLING APPARATUS 6Sheets-Sheet 5 Filed Oct. 11, 1967 |0\ FIG.5

INVENTOR ROY J. BROWN Aug. 19, 1969 I J, BROWN 3,461,825

SHEET-HANDLING APPARATUS Filed Oct. 11, 1967 6 Sheets-Sheet 4 FIG.7

28 T f 4 a 0 FM) 3 12 a0 49 \IO FIG.8

INVENTOR ROY J. BROWN ATTORNEYS Filed Oct. .11. 19s? W 196,9 R. J. BROWN3,461,825

I sarmwmmomm APPARATUS v 6 Sheets-Sheet s I Aug- 19, 1969 R. ,1. BROWN3,461,825

SHEET-HANDLING APPARATUS Filed Oct. 11, 1967 v s Shets-Sheet 6 INVENTOR.

ROY J. BROWN /WWW ATTORNEYS United States Patent US. Cl. 11210 20 ClaimsABSTRACT OF THE DISCLOSURE Sheet-handling apparatus capable of moving aflexible sheet from a first location to a second location while thesheet is vertically disposed and freely hangs from a first conveyor.Means is provided to move the sheet off and away from the first conveyorand onto a second conveyor which moves the sheet in a generallyhorizontal plane. The apparatus is especially adapted for making bagswherein a first sewing machine positioned at the first location stitchesopposed side margins of the sheet after the latter has been folded uponitself and as the sheet is manually fed into the first sewing machine. Asecond sewing machine adjacent to the second conveyor stitches opposedend margins of the sheet as the sheet moves in the horizontal plane.Means is provided to align the end margins of the sheet when the latteris vertically disposed.

This invention relates to improvements in sheet handling equipment and,more particularly, to a machine for making bags from flexible sheetmaterial, such as burlap or the like.

The apparatus of the present invention operates to move a flexible sheetalong a first path from a first location to a second location while thesheet hangs freely in a substantially vertical plane. At the secondlocation, the sheet, while still vertically disposed, is shiftedlaterally and then is moved along a second path with the sheet in asubstantially horizontal plane or at least in an inclined position. Afirst conveyor engages an upper margin of the sheet and allows thelatter to hang freely and move in the vertical plane. A transfer bar atthe second location quickly moves the upper margin of the sheetlaterally of and away from the first conveyor so that the sheet assumesa position in another vertical plane. A second conveyor then grasps theupper margin of the sheet and moves the latter in a substantiallyhorizontal plane.

Adjacent to the transfer bar is a device for aligning a pair of adjacentvertically disposed marginal edges of the sheet while the latter is in avertical plane. As the sheet moves from the vertical plane to thehorizontal plane, the aforesaid marginal edges remain in alignment eventhough one edge is above the other.

While the apparatus of this invention may be adapted for a number ofdifferent uses, it is especially adapted for bag-making operations whichrequire that a bag be made from a single sheet of bag material. Textilematerials, such as burlap and other fabrics, can be used with theinvention to make bags. Also, the invention can be used to make bagsfrom synthetic materials, such as polypropylene or the like.

As used with the invention, a sheet is folded upon itself to present apair of side marginal edge portions and a pair of end marginal edgeportions. If the sheet is of a synthetic material suitable bonding meansmay be applied to the marginal edge portions. A pair of sewing machinesare used for stitching the side and end marginal edge portionsrespectively if the sheet i a textile material and when the folded sheetis properly oriented relative to the sewing machines. In this way, thestitched sheet will form an open end bag whose one side and bottom are"ice stitched by the sewing machines and whose other side is formed bythe fold line of the sheet.

The first sewing machine will be manually fed by an operator who folds asheet so that the side and end marginal edge portions are adjacent toeach other. Generally, the adjacent side margins of the sheet arestitched by the first sewing machine but the invention is constructed sothat either pair of edge portions can be stitched by the first sewingmachine. After the operator starts the sheet into the first sewingmachine, further operations in handling the sheet are automatic andpositioning of the sheet, aligning the end margins of the sheet, andstitching the end margins can all be done without operator attention.The invention is, therefore, adapted for the high volume production ofbags with a minimum of manual operations.

Prior bag making machines which involve stitching a fabric sheetgenerally operate to move a sheet through the various steps of a bagmaking operation while the sheet remains in a substantially horizontalplane. A major problem stemming from the use of such machines is thedifliculty in aligning the adjacent marginal edge portions of the sheetto be stitched. Since the sheet is horizontally disposed, one marginaledge portion overlies the other edge portion and the fabric mustoftentimes be slightly stretched along its length to bring its marginaledge portions into alignment with each other. Such stretching is usuallynot done uniformly along the length of a sheet and tends to destroy thealignment so that the marginal edges become askew with respect to eachother. Also, the friction forces between the engaging side portions ofthe sheet prevent the edges from becoming properly aligned since anymovement of one side portion of the sheet usually causes some movementof the other side portion.

If the marginal edges are not properly aligned when they are stitched,the bag which is formed by the stitching operation may be rejected asnot conforming to required standards. Generally, most bag standardsrequire that the stitching line be uniformly spaced a minimum distancefrom adjacent marginal edges of the fabric sheet. If this standard isnot attained, the bag will not have the proper strength characteristicsand, if the standard is attained at the expense of forming the stitchingline beyond the minimum distance from the marginal edge, the capacity ofthe bag will be reduced.

The present invention avoids these problems by hanging the sheet in asubstantially vertical plane before a pair of marginal edge portions ofthe sheet are stitched, so that the edge portions can become properlyaligned with each other without interference from friction forcesbetween the opposite sides of the sheet. Also, this alignment ismaintained as the sheet moves through a stitching station, whereby thesheet is stitched along a line which conforms to the required standards.To this end, the apparatus of the invention allows the bag to hang fromand to be moved by a conveyor so that the edge portions to be stitchedwill be vertically disposed for alignment purposes. After the alignmenthas been made, the sheet is moved in the horizontal plane so that thealigned marginal edge portions can be stitched to form the correspondingextremity of the bag.

Bags of different sizes can be made by utilizing the teachings of thisinvention. Also, the invention provides for the stacking of completedbags so that the bags can be taken in a stack to a storage area or apoint of use.

The primary object of this invention is, therefore, to provide improvedsheet handling apparatus which advances a flexible sheet along a firstpath while the sheet hangs in a substantially vertical plane and thenmoves the sheet along a second path extending transversely of the firstpath so that a pair of opposed, adjacent marginal edge portions of thesheet can be readily aligned with each other when the sheet isvertically disposed and can be held in alignment as the sheet ishorizontally disposed to permit the apparatus to be used for making bagsof the type which are stitched along one side and across the bottom.

Another object of this invention is to provide a bag making machinewhich is capable of moving a flexible sheet in a vertical plane foldedupon itself along a predetermined path of travel after a first pair ofadjacent marginal edge portions of the sheet have been stitchedtogether, so that a second pair of adjacent marginal edge portions ofthe sheet can be vertically disposed and can become aligned with eachother before the sheet is moved in a horizontal plane with the secondmarginal edge portions disposed to be stitched as the sheet moves in thehorizontal plane.

A further object of this invention is the provision of a bag makingmachine of the type described which is provided with an improvedconveyor which can be releasably attached to an upper margin of a sheetto move the latter in a vertical plane whereby the sheet will hang fromthe conveyor to permit alignment of the aforesaid marginal edge portionsand allow the sheet to be released from the conveyor after the alignmenthas been completed.

Yet another object of this invention is to provide a bag making machineof the aforesaid character wherein the machine is provided with animproved transfer mechanism for quickly moving the sheet laterally ofand away from the conveyor, so that the sheet can become coupled to asecond conveyor and allow the first conveyor to operate continuously tosuccessively advance a number of sheets to the transfer region.

A further object of this invention is to provide a bag making machine ofthe type described wherein the machine has improved alignment meansacross the path of travel of the suspended sheet which is capable offorcing the leading marginal edges of the sheet toward and intoengagement with vertically spaced stops, when the sheet is verticallydisposed, so that the marginal edges will become aligned with each otherto permit the respective margins of the sheet to be stitched together asthe sheet is moved in a horizontal plane through a sewing machinedisposed in the path of travel of the aligned marginal edges.

Other objects of this invention will become apparent as thespecification progresses, reference being had to the accompanyingdrawings for an illustration of a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a front elevational view of the bag sewing machine of thepresent invention;

FIG. 2 is an elevational view of one side of the machine looking in thedirection of line 22 of FIG. 1;

FIG. 3 is an elevational view of the opposite side looking in thedirection of line 33 of FIG. 1;

FIG. 4 is a top plan view of the machine looking in the direction ofline 4-4 of FIG. 1;

FIG. 5 is a fragmentary cross section view taken along line 55 of FIG.4;

FIG. 6 is an enlarged cross sectional view taken along line 66 of FIG.1;

FIG. 7 is an enlarged fragmentary front elevational view of the transferbar forming a part of the apparatus;

FIG. 8 is an enlarged top plan view of the apparatus;

FIG. 9 is an enlarged fragmentary side elevational view of part of themachine;

FIG. 10 is a top plan view of the structure shown in FIG. 9; and

FIG. 11 is a vertical section showing the way the sheet becomes attachedto the first conveyor.

GENERAL OPERATION The bag sewing machine of the present invention,broadly denoted by the numeral 10, includes a table-like support 12adapted to be disposed on a floor or other supporting surface. Machine10 has two sewing machines 14 and 16 of substantially conventionalconstruction, the machines being adapted to stitch first and secondpairs of adjacent marginal edge portions of a sheet folded upon itself,whereby the stitched edge portions will form one side and the bottom ofan open top bag. Machine 10 is essentially automatic except that anoperator stationed adjacent to sewing machine 14, feeds one pair ofadjacent edge portions of the sheet into sewing machine 14. After thestitching of the sheet has commenced, a first conveyor or advancingmeans 18 engages the stitched margin of the sheet as it progressivelymoves out of and away from sewing machine 14, Conveyor 18 allows thesheet to hang freely and be disposed in a vertical plane.

The sheet is then advanced by conveyor 18 while hanging therefrom to atransfer location 20 adjacent to and extending longitudinally of ashiftable transfer bar 22 (FIGS. 4, 5 and 8). From the transferlocation, the sheet is moved laterally by transfer bar 22 out of coupledrelationship to conveyor 18 into coupled relationship with a secondconveyor 24 which moves the sheet in a direction laterally of and awayfrom transfer location 20 while the sheet is in a substantiallyhorizontal plane. When the sheet is vertically disposed, its second pairof marginal edge portions are aligned by an edge aligning devicedisposed across the path of the hanging sheet. As the sheet is moved inthe horizontal plane, these second marginal edge portions move throughsewing machine 16 and are stitched together. A stacking device 26adjacent to the downstream end of second conveyor 24 grips the completedbag and moves it to a stacking location at which it is dropped andstacked on bags previously mad:

An endless, flexible double belt unit 28 adjacent to sewing machine 14has a generally horizontal stretch 30 for urging a sheet 34 along ahorizontal path after a first pair of marginal edge portions of thesheet such as the side edge portions have been manually fed throughsewing machine 14 and have been stitched together by the sewing needle32. The operator guides sheet 34 into the path of needle 32 afterfolding the sheet upon itself to present the adjacent side marginal edgeportions and the adjacent end marginal edge portions. Stretch 30 of beltunit 28 is vertically shiftable since the lower pulleys of unit 28 aremounted on a rotatable bar 37 (FIG. 9) pivoted on a shaft 39 extendingoutwardly from vertical plate 35 and carrying pulley 41. This movementaccommodates sheets of different thicknesses. A spring 43 biases one endof bar 37 upwardly and a shiftable screw 33 provides for tensionadjustment of belt unit 28. An idler pulley 45 carried on a bar 47pivoted on shaft 49 serves to maintain tension on belt unit 28. Spring51 biases bar 47 in a counterclockwise direction when viewing FIG. 9.

A thread cutting unit 53 is disposed on sewing machine 14 and includes ablade 55 secured to a shiftable piston rod 57 of a fluid actuated pistonand cylinder assembly 59. Assembly 59 is controlled by a fluid valve(not shown) actuated by an electrical switch 61 secured to a bracket 63having a slot 65. A bolt 67 extends through slot 65 and adjustablymounts bracket 63 on the end plate 69 of sewing machine 14. The cylinderof assembly 59 is also mounted in a suitable manner on end plate 69 sothat blade 55 will move downwardly and against a butt plate (not shown)for severing a thread on the butt plate.

Switch 61 is actuated by an extension 71 extending laterally from onearm 73 of a crank 75 pivoted on bracket 63. The other arm 77 of crank 75is pivoted on a vertical plate or shoe 79 which normally rests on thesheet supporting surface of sewing machine 14. Another arm 81 pivoted tobracket 63 and shoe 79 is disposed in parallelism to arm 77 so that thelower edge of shoe 79 remains parallel with the aforesaidsheet-supporting surface as the shoe is elevated when a sheet passesbeneath it.

As shoe 79 is raised, extension 71 lifts the actuating arm 83 on switch61 to actuate the same. This action lifts blade 55 away from the buttplate and, when shoe 79 is allowed to descend, the switch openspermitting a spring in the cylinder of assembly 59 to force piston rod57 and thereby blade 55 downwardly, whereby the blade will cut thethread on the butt plate. Slot 65 in bracket 63 allows the position ofshoe 79 to be adjusted so that the length of the thread tailing fromsheet 34 (after the latter has been stitched by sewing machine 14) to bevaried.

Sewing machine 16 also has a thread cutting unit substantially identicalto cutting unit 53. However, the electrical switch of the thread cuttingunit corresponding to sewing machine 16 will not only cause the shiftingof the cutting blade but will operate to energize and deenergize themotor which drives sewing machine 16. The operation of this drive motorwill be a function of the location of a sheet to be stitched thereby sothat sewing machine -16 will be turned on before the sheet reaches itssewing needle.

First conveyor 18 comprises an endless, flexible belt 40 having aplurality of sharp pins 42 projecting outwardly therefrom in the mannershown in FIGS. 4 and 8. Belt 40 passes about a number of pulleys whichare arranged to form a pair of stretches 44 and 46 (FIG. 4) with stretch44 being substantially parallel to stretch 30 of belt 28 and stretch 46extending along and through transfer location 20. Belt 40 is driven inthe direction of arrow 48 (FIG. 8) by a motor (not shown) secured tosupport 12 and coupled to the shaft 50 on which is mounted a pulley 52about which belt 40 is disposed. Belt 40 will move at a predeterminedspeed sufficient to allow a sheet 34 to be separated therefrom bytransfer bar 22 without having to stop belt 40.

As belt 40 rounds a second pulley 54, the pins 42 penetrate a verticallydisposed portion 83 (FIG. 11) of sheet 34 as the latter moves away fromsewing needle 32. Portion 83 is presented to pins 42 because a firstplate 85 having an inclined edge 87 lifts the stitched margin of thesheet and a guide bar 89 having a pair of spaced, angled surfaces 91 atone end thereof urges portion 83 laterally and into coupled relationshipto pins 42. Surfaces 91 are across the path of travel of portion 83 andthe latter is limited in its upward movement over plate 85 by a knurleddisc 93 mounted on shaft 49 and is rotatable therewith. Plate 85 has aslot 95 (FIG. 9) for permitting pins 42 to extend in proximity toportion 83. Guide bar 89 has an edge 97 (FIG. which holds portion 83 onpins 42 as the sheet moves along stretch 44.

As sheet 34 moves along stretch 44, it hangs freely from belt 40 in agenerally vertical plane. No structure intersects this vertical plane sothat the sheet will move uninterruptedly under the influence of belt 40.

FIGS. 4 and 8 show how belt unit 28 is moved in response to the movementof belt 40. Shaft 56 for pulley 54 has a bevel gear 58 in mesh with asecond bevel gear 60 secured to shaft 49 on which is mounted a pulley 64coupled with belt unit 28 (FIG. 2). Disc 93 (not shown in FIGS. 4 and 8)also rotates with pulley 64.

Guide bar 89 has a curved portion 99 which follows the path of belt 40as the latter moves about a third pulley 70. As pins 42 move aroundpulley 70, they spread apart so as to more assuredly hold sheet on belt40. Tension in belt 40 can be controlled by a fourth pulley 72 carriedon a threaded shaft 74 shiftably mounted in a sleeve 76 secured to theupper surface 78 of a support plate 80 forming a part of support 12.

Transfer bar 22 includes three articulated sections 82, 84 and 86,section 84 being hingedly connected to section 82 and section 86 beinghingedly connected to section 84 as shown in FIGS. 5 and 7. Section 82is secured in any suitable manner to the upper surface 78 of supportplate 80 (FIG. 5) so that the three sections extend longitudinally ofstretch 46 of belt 40. An extension 88 is secured to section 86 in anysuitable manner adjacent to the central part thereof and the extensionis secured to the outer end of a piston rod 90 forming a part of a fluidactuated piston and cylinder assembly 92 mounted in any suitable manneron upper surface 78. Thus, as piston rod 90 moves toward sections 82, 84and 86, the sections are moved from collapsed or retracted positions toexpanded positions; conversely, movement of the rod 90 in the oppositedirection causes the sections to retract into the positions thereofshown in FIG. 5.

Section 86 has a plurality of teeth 94 on the outermost longitudinaledge thereof. These teeth are adapted to move into engagement with sheet34 and beneath stretch 46 so as to force sheet 34 off and away from pins42 and into coupled relationship with second conveyor 24 when rod 90 isforced out of its cylinder. As shown in FIG. 7, each tooth has aninclined edge and an edge perpendicular to the path of travel of belt 40past transfer bar 22. This tooth shape allows for more effective removalof sheet 34 from pins 42 since the teeth are effectively pointingdownstream of the path of belt 40 and allow the sheet to be movedlaterally of this path even though the sheet will continue to move underthe influence of its own inertia longitudinally of this path.

FIG. 5 illustrates that section 86 of bar 22 is inclined relative topins 42 to cause rapid separation of sheet 34 therefrom. Sections 82,84, and 86 of transfer bar 22 can be made up in segments as shown inFIG. 7, whereby the length of bar 22 can be increased or decreased asdesired to adapt machine 10 for making bags of different sizes. In thealternative, each of the sections of bar 22 can have a fixed length toaccommodate bags of both large and small sizes.

A channel member 103 (FIGS. 9 and 10) attached by a hinge to a bracket107 overlie stretch 46 of belt 40 and has a lip 109 which holds sheet 34on pins 42 as the sheet moves toward location 20. A spring 111 biaseschannel member 103 downwardly but allows the latter to swing upwardlywhen transfer bar 22 displaces sheet 34 to one side of stretch 46.

An edge aligning device 96 is secured to support 12 adjacent to one endof transfer location 20 in alignment with the path of travel of sheet34. Device 96, shown in detail in FIG. 6, includes a pair of side plates98 and 100 which are spaced apart and are disposed on opposed sides ofthe path of travel of sheet 34. These plates are connected together bythreaded fasteners 102 (only one of which is shown in FIG. 6). Eachfastener 102 has a cylindrical spacer 104 thereon in the region betweenplates 98 and 100 and the various spacers 104 are vertically aligned andserve as stops for the leading marginal edges of side portions 34a and34b of sheet 34. An extension plate 101 (FIGS. 2 and 6) extends downwardfrom plates 92 and 100 and is vertically aligned with stops 104. Plate101 serves as an abutment for the lower leading edge portions of sheet34 to prevent the latter from becoming askew at its lower regions whenits upper leading edge portions engage stops 104.

Plates 98 and 100 are relatively convergent as spacers 104 areapproached and also form a fluid passage 106 which is in fluidcommunication with the regions between spacers 104. Passage 106 is alsoin fluid communication with a fluid chamber 108 in housing 110 having anopening 111 connecting passage 106 and chamber 108. A second opening 112in housing 110 places chamber 108 in fluid communication with a conduit114 leading to the air intake side of a blower 116 having an exhaustoutlet 118. A motor 120 operates blower 116 and evacuates chamber 108and thereby passage 106 so that a suction force will be exerted on themarginal edges of side portions 34a and 34b when the latter are adjacentto spacers 104. The edges are thus drawn against spacers 104 and arealigned thereby. A pair of baflles 122 mounted in chamber 108 aredisposed to decrease the speed of the air flow moving between openings111 and 112, while maintaining the speed of the air flow between spacers104 at a desired maximum value. To this end, baflles 122 are divergentas Opening 112 is approached.

In practice, transfer bar 22 will be shifted in a direction to movesheet 34 off pins 42 before the sheet has reached stops 104. However,the inertia of the sheet and the suction force exerted by device 96 willassure that the leading edges of the sheet will move into the positionsshown in FIG. 6. An electric eye or a suitable limit switch can be usedto actuate assembly 92 to cause the movement of transfer bar 22.

Second conveyor 24 includes a series of upper belt and pulley assemblies124 and a series of lower belt and pulley assemblies 126, there being anassembly 126 for each assembly 124, respectively. Each assembly 124includes a belt 128 coupled with pulleys carried by a verticallydisposed plate 130 secured in any suitable manner to sup port 12. Eachbelt 128 has a lower horizontal stretch 132 which is normally injuxtaposition to and overlies the upper horizontal stretch 134 of acorresponding belt 136 on an assembly 126. Thus, stretches 132 and 134of each pair of assemblies 124 and 126 provides means for gripping aportion of sheet 34 to advance the same in a substantially horizontalplane in the direction of arrow 138 (FIG. the direction of movement ofboth stretches 132 and 134. The sheet is thereby conveyed away fromtransfer location in the horizontal plane and toward stacker 26. Eachbelt 136 is coupled to a pair of spaced pulleys 140 and 142 which arerotatable about respective axes disposed below a top plate 144 having anopening 146 for pulley 140 so that the corresponding upper stretch 134of belt 136 will be supported by plate 144, to prevent sagging of thisstretch.

A drive shaft 148 (FIGS. 2 and 5) common to each assembly 124 (FIG. 4)extends parallel to transfer location 20. Similarly, a drive shaft 150parallel to shaft 148 and disposed therebelow is common to assemblies126. A drive motor 152 mounted in any suitable manner on support 12 iscoupled by an endless, flexible drive chain 154 to shaft 150 and thelatter is, in turn, coupled by meshed spur gears 156 and 158 to driveshaft 148. Thus, these shafts are rotated in opposite directions so thatstretches 132 and 134 move in the direction of arrow 138.

Second conveyor 24 also includes a nip roll means for forcing sheet 34into driving relationship with belts 136 after the sheet has beenseparated from belt 40 by transfer bar 22. To this end, a pair of cranks160 are rotatably mounted at spaced locations on shaft 148 (FIG. 4).Each crank 160 includes a pair of rigidly interconnected arms 162 and164, arm 162 having a shaft 166 rotatably mounted thereon with the shafthaving a number of nip rolls 168 rigidly mounted at spaced locationsthereon for rotation therewith. As cranks 160 rotate in a clockwisesense when viewing FIG. 5, the nip rolls are caused to move intoengagement with sheet 34 after the latter has been separated from belt40 by transfer bar 22 and the nip rolls force the sheet into engagementwith the moving I belts 136. Since shaft 166 is freely rotatable on arms162, the sheet is forcibly driven between stretches 132 and 134 of belts128 and 136 respectively so that the sheet is gripped by these stretchesand conveyed toward stacker 26.

To rotate cranks 160, a pair of piston and cylinder assemblies 170 isprovided. Each assembly 170 has a piston rod 172 whose outer end ispivotally coupled to the outer end of the corresponding arm 164 (FIG.5). Thus, as assemblies 170 are simultaneously energized, cranks 160will rotate together to cause nip rolls 168 to move simultaneously intoengagement with the sheet. There will be an extremely small time delay(of the order of milliseconds) between the time when assembly 92 isactuated and assemblies 170 are actuated. Thus, the sheet is engaged, bythe nip rolls at the proper time to assure that the sheet will becoupled to conveyor 24.

Means is provided for second conveyor 24 to hold the aligned marginaledges of side portions 34a and 34b together as the sheet is moved bybelt stretches 132 and 134 toward stacker 26. To this end, a double beltunit 174 having a pair of endless, flexible belts 176 extendslongitudinally of second conveyor 24 and has an extremity adjacent toalignment device 96. Each belt 176 has a lower stretch 177 which forcesthe side portions 34a and 341) into engagement with moving beltstructure (not shown) which extends along the upper surface of top plate144 and terminates just short of the sewing needle of sewing machine 16.Thus, side portions 34a and 34b will remain properly aligned with eachother as they pass through sewing machine 16. One of the nip rolls 168(FIG. 1) is positioned to force the marginal edge portions of the sheetinto sliding engagement with the upper surface of top plate 144. Also, aweighted roller 179 carried by a freely pivoted bar 181 forces stretches177 downwardly to assure that the sheet will be properly driven throughsewing machine 16.

Sewing machine 16 is also of conventional construction and is driven bya belt and pulley assembly 178 connected to the drive shaft (FIG. 3) ofa motor (not shown). Control means of the type utilized with cuttingunit 53 is provided to actuate sewing machine 16 as a sheet 34 is movedtoward the same. Thus, sewing machine 16 does not have to be operatedcontinuously.

Stacker 26 at the downstream end of second conveyor 24 is of anysuitable type. For purposes of illustration, it has a number of pairs ofarms 182 and 184 with arm 182 of each pair being movable beneath amoving sheet 134 to force the sheet into engagement with thecorresponding arm 184. In this way, the sheet is gripped between eachpair of arms and the latter are then moved with the other pairs of armsas a unit further downstream with respect to second conveyor 24 to carrythe sheet therewith, whereby the sheet may be deposited in a stack tothe rear of machine 10.

A first fluid actuated piston and cylinder assembly 186 causes arms 182to move so that they underlie sheet 134 and force the latter intoengagement with respective arms 184. A second fluid piston and cylinderassembly 188 then causes the pairs of arms to move as units so as todraw the sheet away from machine 10 to the stacking location. To thisend, a crank unit 190 having a first arm 192 pivotally connected to theouter end of a piston rod 194 forming a part of assembly 188 has asecond arm 196 rigid to arm 192 for pivotally mounting assembly 186thereon for movement rearwardly of machine 10 as arm 192 rotates in aclockwise sense when viewing FIG. 3 about an axis through a. pin 198secured to a fixed arm 200. A link 202 coupled to assembly 186 causesthe latter to swing toward the horizontal as it moves rearwardly of themachine. Arms 182 and 184, mounted on shafts 204 and 206 respectivelywhich extends laterally from assembly 186, will have previously engagedand gripped sheet 34 before the rearward movement of assembly 186 underthe influence of crank 190. Thus, the movement of crank unit 190 assuresrearward movement of a sheet 34 gripped by arms 182 and 184.

DETAILED OPERATION Machine 10 is initially placed in operation when anoperator positioned adjacent to sewing machine 14 feeds a first pair ofadjacent marginal edge portions of sheet 34 folded upon itself towardsewing needle 32 of sewing machine 14. Generally, a stack of sheets willbe located adjacent to the operator position and the operator will takethe sheets, one by one, and fold each sheet upon itself so that themarginal edge portions which will define the side of a bag are injuxtaposition to each other. As these marginal edge portions are fedthrough sewing machine 14, they are stitched along a line uniformlyspaced from the edges of the side marginal edge portions of the sheet.The operator can present the marginal edge portions to sewing machine 14in a manner to provide a particular seam for the bag, such as an exportseam or the like. A guide may be provided as part of sewing machine 14to direct the marginal edge portions of the sheet therethrough.

As soon as the sheet begins to move out of and away from sewing machine14, the stitched margin of the sheet is moved by surfaces 87 and 91(FIGS. 9, and 11) into coupled relationship to pins 42 and the lattercarry the sheet successively along stretches 44 and 46 of belt 40. Thebelt will be continuously moving and its speed will be correlated withthe speed of movement of belt 28 which facilitates the movement of thesheet through sewing machine 14.

As pins 42 advance the sheet toward location 20, the sheet freely hangsfrom belt 40 in a vertical plane. The end marginal edge portions which,when stitched together, will define the bottom of a bag, move in advanceof the remainder of the sheet and eventually move into proximity tospacers 104 in the manner shown in FIGURE 6.

Transfer bar 22 has an electric eye or a limit switch (not shown)associated therewith for actuating piston and cylinder assembly 92 as afunction of the position of the sheet at location 20. Thus, when thesheet trips the limit switch, transfer bar 22 is immediately shiftedtoward second conveyor 24 and forcibly engages the sheet to cause thelatter to shift away from pins 42 and toward second conveyor 24. Thislifts channel member 103 which had previously operated to hold the sheeton pins 42 as the sheet moved toward location 20. The end marginal edgesof side portions 34a and 34b will then become aligned with each otherunder the influence of device 96.

Within a relatively short time after transfer bar 22 begins to movelaterally, piston and cylinder assemblies 170 are energized to causecranks 160 to rotate about shaft 148 in a clockwise sense when viewingFIGURE 5. Thus, nip rolls 168 force the sheet into engagement with belts136 at least until the sheet passes between stretches 132 and 134. Whenthis occurs, the sheet is effectively gripped and caused to move towardstacker 26. The nip roll corresponding to belts 176 forces the alignedmarginal edge portions into engagement with the belt structure extendingalong surface of plate 144 and, to facilitate this action, a curvedextension defining a convex surface can be provided on plate 144 to moreassuredly maintain the marginal edge portions in alignment with eachother.

The sheet is conveyed toward stacker 26 and the end marginal edgeportions are moved in stitching relationship through sewing machine 16.Thus, the end margin of a bag is formed with the stitch line beinguniformly spaced from the end marginal edges of the sheet.

A limit switch will also be provided to actuate stacker 26 so that arms182 and 184 thereof will move into gripping relationship with the sheetas the latter moves downstream of second conveyor 24. Stacker 26 willthen advance the sheet to a location away from machine 10, whereuponarm-s 182 and 184 will separate to allow the sheet to be dropped onto astack or other suitable structure.

Immediately after one sheet is fed through sewing machine 14, theoperator can prepare a second sheet to be stitched by sewing machine 14and the second sheet can be stitched as the first sheet is moving towardlocation 20. In this way, a relatively large number of sheets can beprocessed in a minimum of time with the only manual step being to feedthe sheet initially through the first stitching station.

The way in which a sheet is separated from pins 42 also contributes tothe relatively high volume production of bags by machine 10. This is dueto the fact that transfer bar 22 shifts a sheet laterally of belt 40even while the latter continues to move so that one sheet is displacedlaterally of location as a succeeding sheet carried by pins 42 movestoward this location. Thus, one sheet may be moved into coupledrelationship with second conveyor 24 as the succeeding sheet isadvancing toward location 20.

Machine 10 can continue to operate in the above manner so long as sheetsare fed by the operator through sewing machine 14. Except for the stepof feeding sheets into sewing machine 14, the operation of machine 10 isessentially automatic and the bags formed thereby will conform todesired standards.

While one embodiment of this invention has been shown and described, itwill be apparent that other adaptations and modifications of this devicecan be made without departing from the true scope of the invention.

What is claimed is:

1. A machine for making a bag from a sheet of bag material comprising: afirst sewing machine for stitching a first pair of adjacent marginaledges of the sheet to form one margin of a bag and to present a secondpair of adjacent marginal edges of the sheet extending laterally fromsaid one margin; means adjacent to the first sewing machine for engaginga margin of the sheet as the latter move away from the first sewingmachine and for advancing the sheet to a location remote therefrom withthe sheet hanging from said engaging and advancing means and disposed ina generally vertical plane; means at said location for separating thesheet from said engaging and advancing means; a second sewing machinespaced from said location; and means adjacent to said location forconveying the sheet in a plane transverse to the vertical plane pastsaid second sewing machine with said second marginal edges in a positionto be stitched thereby after said sheet has been separated from saidadvancing means, whereby a second margin of the bag is formed.

2. A machine as set forth in claim 1, wherein said separating means isdisposed to shift the sheet laterally of the path of travel of saidengaging and advancing means and into coupled relationship to saidconveying means.

3. A machine as set forth in claim 1, wherein said conveying meansincludes structure for holding said second marginal edges in alignmentas said sheet is conveyed past said second sewing machine.

4. A machine as set forth in claim 1, wherein said conveying meansincludes belt structure movable away from said location and bearingstructure for forcing the sheet into engagement with said belt structureafter said sheet has been separated from said advancing means.

5. A machine as set forth in claim 1, wherein said engaging andadvancing means includes first endless belt structure having a firsthorizontal stretch and mean for releasable connection with said onemargin of the sheet, said separating means including a bar mounted formovement laterally of the path of travel of said first stretch and beingforcibly engageable with the sheet to urge the latter away from saidfirst stretch as the sheet hangs from said engaging and advancing means,said conveying means including second endless belt structure having asecond horizontal stretch extending laterally of and movable away fromsaid path, and nip roll means adjacent to said second stretch forforcing the sheet into engagement therewith after the sheet has beenurged away from said first stretch.

6. A machine as set forth in claim 1, wherein is included structure inthe path of travel of the sheet as it moves away from said first sewingmachine for forcing the sheet toward and into coupled relationship tosaid engaging and advancing means.

7. A machine as set forth in claim 6, wherein said engaging andadvancing means includes an endless belt having a number of spaced pinsextending outwardly from one side thereof, said structure including afirst member having a surface for lifting said one margin of the sheetto present a vertically disposed face, and a second member having asurface for progressively moving said vertically disposed face towardsaid pins, whereby the sheet will engage the pins at said verticallydisposed face and will be carried by the belt to said location.

8. A machine as set forth in claim 1, wherein is provided means adjacentto said first sewing machine for cutting the thread thereof as afunction of the position of the sheet relative thereto and after saidone margin has been stitched thereby.

9. A machine for making a bag from a sheet of bag material comprising:means for securing a first pair of adjacent marginal edge portions ofthe sheet together to form one margin of a bag and to present a secondpair of adjacent marginal edge portions of the sheet extending laterallyfrom said one margin; means adjacent to said securing means for engagingthe sheet as the later moves away from the securing means and foradvancing the sheet to a location remote therefrom with the sheethanging from said engaging and advancing means and disposed in agenerally vertical plane; means at said location for separating thesheet from said engaging and advancing means; means spaced from saidlocation for connecting the second pair of marginal edge portionstogether; and means adjacent to said location for conveying the sheet ina plane transverse to the vertical plane past said connecting means withsaid second marginal edge portions in a position to be connected therebyafter said sheet has been separated from said engaging and advancingmeans, whereby a second margin of the bag is formed.

10. A machine for making a bag from a flexible sheet of bag materialfolded upon itself to present a pair of adjacent side margins and a pairof adjacent end margins comprising: a first sewing machine for stitchingsaid side margins of the sheet to form one side of a bag; means adjacentto the first sewing machine for engaging the stitched side margins ofthe sheet as it moves away from said first sewing machine and foradvancing the sheet to a location remote from said first sewing machineas the sheet hangs from said engaging and advancing mean in a generallyvertical plane; means adjacent to said first sewing machine for urgingthe stitched side margins into coupled relationship to said engaging andadvancing means; means adjacent to said location for aligning the endmargins of the sheet with each other as the sheet is verticallydisposed; means at said location for separating the sheet from saidengaging and advancing means; a second sewing machine spaced from saidlocation; and means adjacent to said location for conveying the sheet ina generally horizontal plane past said second sewing machine with saidend margins disposed to be stitched by the second sewing machine,whereby one end of the bag is closed.

11. A machine as set forth in claim 10, wherein said aligning meanscomprises a suction device.

12. A machine as set forth in claim 11, wherein said device has meansdefining a pair of vertically spaced stops and a vacuum chambercommunicating with the space between the stops, said engaging andadvancing means being disposed to shift the sheet toward said devicewith the end margins of the sheet substantially vertically disposed andhorizontally aligned with the stops.

13. A machine as set forth in claim 10, wherein is provided meansadjacent to said engaging and advancing means for releasably holding thesheet thereon as the sheet is moved to said location.

14. A machine as set forth in claim wherein said separating meansincludes a shiftable transfer bar, actuatable power means coupled withthe transfer bar for shifting the latter transversely of the path oftravel of the engaging and advancing means and into forcible engagementwith the sheet to separate it from the engaging and advancing means, andmeans responsive to the position of the sheet along the path of saidengaging and advancing means for actuating said power means.

15. A machine as set forth in claim 14, wherein said transfer bar has aplurality of sheet-engaging teeth, each tooth having a pair ofconvergent edges with one edge extending longitudinally of and at anangle to said path of travel and a second edge substantiallyperpendicular to said path.

16. In a sheet handling machine a first conveyor having means forreleasable engagement with a sheet along one margin of the latter tocause the sheet to hang freely in a generally vertical plane, saidconveyor being disposed for advancing the sheet along a first, generallyhorizontal path as the sheet hangs from the first conveyor; meansadjacent to said first conveyor for moving the sheet laterally of saidfirst path and away from said first conveyor after the sheet has beenmoved through a predetermined distance along said first path; and asecond conveyor having means for engaging said sheet to move the latterin a generally horizontal plane along a second path extending laterallyfrom the first path.

17. In a sheet handling machine: a first conveyor having means adaptedto engage one margin of a sheet to permit the sheet to hang freely in agenerally vertical plane, said conveyor being disposed to move the sheetalong a first path of travel as the sheet hangs from the conveyor; adevice adjacent to said first path of travel for aligning a pair ofadjacent end marginal edges of the sheet when the sheet is verticallydisposed; means on one side of said first path for urging said sheetlaterally of and away from said first conveyor to separate the sheettherefrom; and a second conveyor extending laterally of said first pathand disposed for movirig the sheet along a second path of travel withsaid sheet disposed in a substantially horizontal plane, said urging'means being disposed to move said sheet into coilipled relationshipwith said second conveyor, whereby the sheet move along said secondpath.

18. In a sheet handling machine, structure for aligning a pair ofadjacent, vertically disposed marginal edges of a movable sh'eet whenthe latter is disposed in a subs-antially vertical planefcomprising:means defining a pair of vertically spaced stops adapted to be disposedin the path of travel of the sheet; and means coupled with the spacebetween said stops for evacuating said space to thereby cause said edgesof the sheet to be urged toward said stops by suction.

19. In a machine as set forth in claim 18, wherein said evacuating meansincludes a vacuum chamber adapted to be coupled to a vacuum source andbeing in fluid communication with said space, and wherein is includedguide structure for directing said sheet toward said stops.

20. In a machine as set forth in claim 19, wherein said guide structureincludes a pair of relatively convergent plates, and wherein is includeda pair of spaced bafiies within said chamber and being relativelyconvergent as said stops are approached.

References Cited UNITED STATES PATENTS 2,630,086 3/1953 Kindseth et al1l211 3,032,341 5/1962 Reist 27179 3,039,409 6/1962 Cordle 112l13,208,416 9/ 1965 Davis 112-11 3,224,394 12/1965 Dobner et a1 112-103,345,963 10/1967 Shoaf 271-79 X 1,738,186 12/1929 Krasa 112-252 ALFREDR. GUEST, Primary Examiner

